Automatic oil extraction equipment

Abstract

The present invention relates to the technical field of transformer insulating oil sampling, and specifically to an automatic oil extraction device, including a sampling box and a sampler arranged in the sampling box, a three-way solenoid valve is fixedly arranged in the sampling box, three interfaces of the three-way solenoid valve are respectively connected to a waste oil discharge pipe, a sampling oil inlet pipe port and a sampling oil outlet pipe port, the sampling oil outlet pipe port includes a central sampling pipe and an outer pipe sleeve placed outside the central sampling pipe with an air sleeve, one end of the outer pipe sleeve is provided with a connecting sleeve for detachable connection with the three-way solenoid valve, the end of the connecting sleeve extends out of the end of the central sampling pipe, a blocking block is slidably arranged in the connecting sleeve, when the blocking block slides along its axial direction in the connecting sleeve, the end of the central sampling pipe close to the connecting sleeve is closed or opened, and the oil discharge port is connected or blocked with the connecting sleeve. When the present invention is used specifically, air and impurities can be conveniently discharged, and repeated rinsing of the central sampling pipe and the sampler is convenient, thereby improving the accuracy of sampling.

Description

Technical Field

[0001] The invention relates to the technical field of transformer insulating oil sampling, and in particular to automatic oil sampling equipment. Background Art

[0002] During long-term use, transformer oil may deteriorate due to oxidation, moisture, pollution, etc., affecting the insulation performance and heat dissipation effect of the transformer. Through regular sampling and testing, oil quality problems can be discovered in time, and corresponding treatment measures can be taken to prevent transformer failures due to oil quality problems. Through regular sampling and testing, problems in transformer oil, such as excessive moisture content and excessive acid value, can be discovered in time, so that timely measures can be taken to deal with them and avoid the expansion of problems.

[0003] When sampling, it is necessary to perform emptying, impurity removal, rinsing and other operations to improve the accuracy and reliability of sampling. At present, the automatic oil extraction device has a built-in three-way solenoid valve. The first port is connected to the transformer body sampling valve (or external pipeline valve) for oil inlet, the second port is connected to the needle of the oil extraction syringe, and the third port is the waste oil discharge port. The stepper motor moves upward in the vertical direction to push the syringe piston to discharge the oil; the pressure of the transformer oil itself is used to inject the oil into the syringe. At this time, the stepper motor moves slowly downward to prevent the push rod from blocking the syringe piston and hindering the oil inlet. When this structure is in use, it is not convenient to discharge the waste oil generated in the process through the waste oil discharge port and the syringe piston repeatedly moves to exhaust, remove impurities and rinse, which affects the accuracy of later detection.

[0004] In the prior art, the patent document with the authorization announcement number CN109211620B discloses a transformer insulating oil sampling device, wherein the oil inlet port of the oil circuit is used to connect with the oil extraction port of the transformer through a connecting pipe, the first oil outlet port is connected with the first sampling device through a connecting pipe, and the first oil outlet port is arranged at the upper part of the sampling box, so that the insulating oil flows from the oil inlet port of the oil circuit to the first oil outlet port from bottom to top, which can reduce the air in the sample oil and improve the accuracy of the test results. When it is used, the first oil outlet port and the first sampling device are connected by a one-way flow connecting pipe. When performing exhaust or rinsing operations, it is not convenient to discharge the waste oil generated in the process, which affects the accuracy of the later detection. Summary of the invention

[0005] The invention provides an automatic oil extraction device to solve the technical problem in the prior art that it is inconvenient to discharge air and impurities when sampling transformer insulating oil, which affects the accuracy of sampling.

[0006] In order to solve the above problems, the present invention provides an automatic oil extraction device adopting the following technical solutions:

[0007] The invention comprises a sampling box and a sampler arranged in the sampling box, wherein a three-way solenoid valve is fixedly arranged in the sampling box, and three interfaces of the three-way solenoid valve are respectively connected to a waste oil discharge pipe, a sampling oil inlet pipe port and a sampling oil outlet pipe port, and the other end of the sampling oil outlet pipe port is connected to the sampler, and the sampling oil outlet pipe port comprises a central sampling pipe and an outer pipe sleeve which is placed outside the central sampling pipe with an air sleeve, and a drainage cavity is formed between the central sampling pipe and the outer pipe sleeve, and an oil drainage port connected to the drainage cavity is arranged on the outer pipe sleeve, and a connecting sleeve for detachably connecting to the three-way solenoid valve is arranged at one end of the outer pipe sleeve, and an end of the connecting sleeve extends out of the end of the central sampling pipe, and a blocking block is slidingly arranged in the connecting sleeve, and when the blocking block slides along its axial direction in the connecting sleeve, the end of the central sampling pipe close to the connecting sleeve is closed or opened, and at the same time, the oil drainage port is connected to or blocked from the connecting sleeve.

[0008] By adopting the above scheme, air and impurities can be easily discharged during the sampling process through the design of the drainage cavity. When the block is at the right end, the central sampling tube is closed, and the oil discharge port is connected to the connecting sleeve, so that part of the waste oil at the connection can be discharged through the oil discharge port to ensure the purity of subsequent sampling. In addition, it is easy to realize repeated rinsing of the central sampling tube and the sampler, thereby improving the accuracy of sampling.

[0009] Further, the blocking block includes a cylindrical plug, a limit plate is provided at one end of the cylindrical plug away from the central sampling tube, an annular sleeve is provided at the end of the limit plate opposite to the central sampling tube, a first sealing block is circumferentially spaced apart on the outer wall of the end of the annular sleeve close to the central sampling tube, one side of the first sealing block extends out of the annular sleeve along the axial direction, and a first matching block is circumferentially spaced apart on the outer wall of the end of the central sampling tube close to the connecting sleeve, and the first matching block corresponds to between two adjacent first sealing blocks.

[0010] With the above technical solution, when the blocking block moves to the right, the spacing distribution between the first sealing block and the first matching block enables the oil sample to enter the drainage cavity through adjacent gaps in an orderly manner, facilitating the discharge of residual oil while avoiding disordered diffusion and waste of the oil sample.

[0011] Furthermore, the outer wall of the annular sleeve is provided with a connecting rod extending along its axial direction and toward a side close to the central sampling tube, the connecting rod corresponds to two adjacent first matching blocks, the free end of the connecting rod is connected with a limit stop ring, and the limit stop ring is sealingly slidably arranged in the discharge cavity.

[0012] The inner wall of the outer pipe sleeve is provided with a left limiting step and a right limiting step for matching with the limiting retaining ring.

[0013] By adopting the above technical solution, the connection rod on the annular sleeve and the limit stop ring connected thereto cooperate with the left and right limit steps on the inner wall of the outer tube sleeve, which facilitates the control of the oil flow path and improves the sampling efficiency. It is also convenient for maintenance and cleaning and improves the safety and stability of use.

[0014] Furthermore, a guide cavity is formed on the outer wall of the outer sleeve, the oil discharge port is arranged on the outer wall of the guide cavity and communicated with the guide cavity, and a through groove for connecting the guide cavity and the discharge cavity is provided on the outer sleeve.

[0015] Furthermore, an annular groove for external plug-in is formed on the connecting sleeve, the outer wall of the annular groove forms a sleeve and the inner wall forms a plug, and second matching blocks are circumferentially spaced on the inner wall of the outer port of the plug, and the second matching blocks are relatively distributed with the first matching blocks. The limiting plate is provided with a second sealing block that is relatively distributed with intervals with the first sealing block, and one side of the second sealing block extends out of the limiting plate along the axial direction of the cylindrical piston, and the distance between the second matching block and the first matching block is greater than the length of the blocking block.

[0016] Furthermore, the outer port of the cannula is a wedge-shaped socket.

[0017] By adopting the above technical solution, the entry and discharge paths of the oil flow can be accurately controlled by positioning the blocking block between the second matching block and the first matching block. The outer port of the insert is a wedge-shaped insert, which can also play an automatic cleaning role during the connection process and scrape off the residual oil on the inner wall of the pipe mouth.

[0018] Furthermore, the end of the sampling oil outlet pipe close to the three-way solenoid valve includes an L-shaped connecting section, and the side of the limit stop ring away from the connecting sleeve is provided with an action rod corresponding to the sliding through the outer pipe sleeve.

[0019] Furthermore, a partition between the central sampling tube and the outer tube sleeve is provided at one end of the drainage cavity close to the sampler, the partition is provided with a through hole, and a unidirectional membrane is fixed above the partition to allow oil to flow from one side close to the sampler to the other side.

[0020] By adopting the above technical solution, the one-way membrane allows the oil to flow unidirectionally from one side close to the sampler to the other side, so that during the exhaust and rinsing operations, the waste oil in the discharge chamber cannot flow back into the sampler, effectively preventing the waste oil from contaminating the sampler and ensuring the cleanliness of the sampler and the accuracy of subsequent sampling.

[0021] Furthermore, the sampler comprises a sampling tube and a piston rod slidably arranged in the sampling tube, and a power mechanism for driving the piston rod to move vertically back and forth is arranged in the sampling box.

[0022] The beneficial effect of the present invention is that air and impurities can be conveniently discharged during the specific sampling process. When the block is at the right end, the central sampling tube is closed, and the oil discharge port is connected to the connecting sleeve, so that part of the waste oil at the connection point can be discharged through the oil discharge port to ensure the purity of subsequent sampling. In addition, through the operation of the block, it is convenient to realize repeated rinsing of the central sampling tube and the sampler, thereby improving the accuracy of sampling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0024] Figure 1 This is one of the structural schematic diagrams of the automatic oil extraction device of the present invention;

[0025] Figure 2 This is the second structural schematic diagram of the automatic oil extraction device of the present invention;

[0026] Figure 3 It is a structural schematic diagram of the three-way solenoid valve in the present invention cooperating with the waste oil discharge pipe, the sampling oil inlet pipe port and the sampling oil outlet pipe port;

[0027] Figure 4 It is a cross-sectional view of the connection between the sampling oil outlet pipe port and one end of the three-way solenoid valve in the present invention;

[0028] Figure 5 for Figure 4 A partial enlarged view of the middle area A;

[0029] Figure 6 is a cross-sectional view of the L-shaped connecting section of the present invention;

[0030] Figure 7 It is a structural schematic diagram of the block in the present invention;

[0031] Figure 8 A cross-sectional view of one end of the sampling oil outlet pipe connected to the sampler in the present invention;

[0032] Fig. 9 It is a schematic diagram of the structure of the L-shaped connecting section in the present invention;

[0033] Fig.10 Schematic diagram of the oil flow direction in the L-shaped connecting section when used for rinsing in the present invention.

[0034] Description of reference numerals:

[0035] 1. Sampling box; 2. Three-way solenoid valve; 21. Waste oil discharge pipe; 22. Sampling oil inlet pipe port; 23. Sampling oil outlet pipe port; 230. L-shaped connecting section; 231. Central sampling pipe; 231a. First matching block; 232. Outer pipe sleeve; 232a. Oil discharge port; 232b. Diversion cavity; 232c. Through groove; 233. Discharge cavity; 234. Connecting sleeve; 234a. Annular groove; 234b. Sleeve; 234c , cannula; 234d, second matching block; 235, partition; 236, one-way membrane; 237, left limit step; 238, right limit step; 3, sampler; 31, sampling tube; 32, piston rod; 4, blocking block; 41, cylindrical plug; 42, limit plate; 421, second sealing block; 43, annular sleeve; 431, first sealing block; 432, connecting rod; 44, limit stop ring; 441, action rod; 5, power mechanism. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] Any number of elements in the drawings is for illustration and not limitation, and any naming is for distinction only and does not have any limiting meaning.

[0038] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0039] Embodiments of the automatic oil extraction device provided by the present invention:

[0040] like Figures 1 to 10 As shown, it includes a sampling box 1, a three-way solenoid valve 2, a sampler 3, a blocking block 4 and a power mechanism 5.

[0041] The three-way solenoid valve 2, the sampler 3 and the power mechanism 5 are all arranged in the sampling box 1, and the block 4 is slidably arranged in the sampler 3. The three interfaces of the three-way solenoid valve 2 are respectively connected to the waste oil discharge pipe 21, the sampling oil inlet pipe port 22 and the sampling oil outlet pipe port 23, and the other end of the sampling oil outlet pipe port 23 is connected to the sampler 3.

[0042] During specific use, the other end of the sampling oil inlet pipe port 22 is connected to the sampling valve of the transformer body.

[0043] In this embodiment, the sampler 3 includes a sampling tube 31 and a piston rod 32 slidably disposed in the sampling tube 31 , and a power mechanism 5 for driving the piston rod 32 to move vertically back and forth is disposed in the sampling box 1 .

[0044] The power mechanism 5 includes a slide rail and a lead screw rotatably supported on the slide rail. A stepper motor driving the lead screw to rotate is provided at one end of the slide rail. A slider is provided through the lead screw and the slider is slidably matched with the slide rail. A horizontal plate is provided at the bottom end of the piston rod 32. One end of the horizontal plate is connected to the slider. The vertical reciprocating movement of the slider drives the piston rod 32 to move upward or downward.

[0045] In this embodiment, the sampling oil outlet pipe port 23 includes a central sampling pipe 231 and an outer pipe sleeve 232 which is placed outside the central sampling pipe 231 in an airtight manner. A drainage cavity 233 is formed between the central sampling pipe 231 and the outer pipe sleeve 232. The outer pipe sleeve 232 is provided with an oil drainage port 232a which is connected to the drainage cavity 233.

[0046] A guide cavity 232b is formed on the outer wall of the outer sleeve 232, the oil discharge port 232a is arranged on the outer wall of the guide cavity 232b and communicates with the guide cavity 232b, and a through groove 232c for connecting the guide cavity 232b and the discharge cavity 233 is provided on the outer sleeve 232.

[0047] One end of the outer tube sleeve 232 is provided with a connecting sleeve 234 for detachable connection with the three-way solenoid valve 2, and the end of the connecting sleeve 234 extends out of the end of the central sampling tube 231. A blocking block 4 is slidably provided in the connecting sleeve 234. When the blocking block 4 slides along its axial direction in the connecting sleeve 234, the end of the central sampling tube 231 close to the connecting sleeve 234 is closed or opened, and at the same time, the oil discharge port 232a is connected or blocked with the connecting sleeve 234.

[0048] Among them, the sampling oil outlet pipe 23 includes a central sampling pipe 231 and an outer pipe sleeve 232, and a drainage cavity 233 is formed between the central sampling pipe 231 and the outer pipe sleeve 232. When the block 4 is sliding and moving, that is, when it is at the right end, the end of the central sampling pipe 231 is in a closed state and the oil discharge port 232a is connected with the connecting sleeve 234, so that part of the waste oil at the connection point can be discharged through the oil discharge port 232a. When the block 4 is at the left end, the end of the central sampling pipe 231 is in an open state, and the oil discharge port 232a and the connecting sleeve 234 are in a blocked state, that is, the oil enters the central sampling pipe 231, enters the sampling cylinder 31 after passing through the central sampling pipe 231, and then is discharged through the drainage cavity 233 and the oil discharge port 232a, so that the air is discharged and repeated cleaning is achieved at the same time.

[0049] Specifically, during use, the drainage cavity 233 formed between the central sampling tube 231 and the outer tube sleeve 232 facilitates the discharge of gas and repeated rinsing during the sampling process, thereby improving the accuracy of oil sampling.

[0050] In this embodiment, the blocking block 4 includes a cylindrical plug 41, and a limiting plate 42 is provided at one end of the cylindrical plug 41 away from the central sampling tube 231, and an annular sleeve 43 is provided at the end of the limiting plate 42 opposite to the central sampling tube 231. The outer wall of the end of the annular sleeve 43 close to the central sampling tube 231 is circumferentially spaced with first sealing blocks 431, and one side of the first sealing block 431 extends out of the annular sleeve 43 along the axial direction of the annular sleeve 43. The outer wall of the end of the central sampling tube 231 close to the connecting sleeve 234 is circumferentially spaced with first matching blocks 231a, and the first matching blocks 231a correspond to between two adjacent first sealing blocks 431.

[0051] During specific use, when the blocking block 4 moves to the right, the first matching blocks 231a and the first sealing blocks 431 are spaced apart, so that the oil flows between adjacent first sealing blocks 431 to between adjacent first matching blocks 231a, enters the drainage cavity 233, and is discharged through the oil discharge port 232a.

[0052] The waste oil at the connection port in the initial state is discharged through a specific gap, avoiding disorderly diffusion and waste of the oil sample.

[0053] Among them, the outer wall of the annular sleeve 43 is provided with a connecting rod 432 extending along its axial direction and toward the side close to the central sampling tube 231, and the connecting rod 432 corresponds to two adjacent first matching blocks 231a. The free end of the connecting rod 432 is connected with a limit stop ring 44, and the limit stop ring 44 is sealingly slidably arranged in the discharge cavity 233.

[0054] The inner wall of the outer tube sleeve 232 is provided with a left limit step 237 and a right limit step 238 for cooperating with the limit stop ring 44. The limit stop ring 44 moves between the left limit step 237 and the right limit step 238. The left limit step 237 and the right limit step 238 are respectively located on both sides of the oil discharge port 232a.

[0055] During specific use, when the limit stop ring 44 abuts against the side of the right limit step 238, the oil drain port 232a and the connecting sleeve 234 are connected, so that the waste oil generated at the connecting sleeve 234 at the beginning can be discharged through the oil drain port 232a; when the limit stop ring 44 is close to the left limit step 237, the oil drain port 232a and the connecting sleeve 234 are blocked and connected to the sampling tube 31, that is, the waste oil generated during exhaust or rinse is discharged from the oil drain port 232a, the limit stop ring 44 abuts against the side of the left limit step 237, and the outer port of the entire connecting sleeve 234 is closed.

[0056] In this embodiment, an annular groove 234a for external plug-in is formed on the connecting sleeve 234, the outer wall of the annular groove 234a forms a sleeve 234b and the inner wall forms a plug 234c, and the inner wall of the outer port of the plug 234c is circumferentially spaced with second matching blocks 234d, the second matching block 234d is relatively distributed with the first matching block 231a, and the limiting plate 42 is provided with a second sealing block 421 that is relatively distributed with a gap with the first sealing block 431, one side of the second sealing block 421 extends out of the limiting plate 42 along the axial direction of the cylindrical piston 41, and the distance between the second matching block 234d and the first matching block 231a is greater than the length of the blocking block 4.

[0057] During specific use, when the blocking block 4 is between the second matching block 234d and the first matching block 231a, the port of the central sampling tube 231 is opened, and the oil enters through the insert 234c, and passes through the second sealing block 421, the first sealing block 431 and the gap formed between the central sampling tube 231 and the cylindrical plug 41 to enter the central sampling tube 231, and then the oil enters the sampling cylinder 31 and then continues to pass through the discharge cavity 233 and is discharged through the oil discharge port 232a. The first operation can realize the exhaust operation, and then the action of the sampler 3 can realize 3-4 times of cyclic oil discharge, thereby achieving the effect of lubrication.

[0058] The outer port of the cannula 234c is a wedge-shaped socket.

[0059] Specifically, the outer wall of the pipe mouth connecting the three-way solenoid valve 2 and the connecting sleeve 234 is provided with a thread, the inner wall of the sleeve 234b is provided with a thread matching therewith, and the sleeve 234b and the outer pipe sleeve 232 are rotationally matched. When the connecting sleeve 234 is installed by a spiral connection, the wedge-shaped socket of the insert 234c will scrape off the residual oil on the inner wall of the corresponding connected pipe mouth, and then discharge it through the oil drain port 232a.

[0060] In this embodiment, the end of the sampling oil outlet 23 close to the three-way solenoid valve 2 includes an L-shaped connecting section 230, and the side of the limit ring 44 away from the connecting sleeve 234 is provided with an action rod 441 corresponding to the sliding through the outer pipe sleeve 232.

[0061] The entire blocking block 4 is driven to move by pulling the action rod 441 .

[0062] Among them, a partition 235 is provided between the central sampling tube 231 and the outer tube sleeve 232 at one end of the drainage cavity 233 close to the sampler 3, and a through hole is provided on the partition 235. A unidirectional membrane 236 is fixed above the partition 235 to allow oil to flow unidirectionally from one side close to the sampler 3 to the other side.

[0063] The one-way membrane 236 is provided to prevent the waste oil in the drainage chamber 233 from entering the sampler 3 during the exhaust and rinsing operations.

[0064] When the automatic oil extraction equipment of this embodiment is used, the three-way solenoid valve 2 is first controlled to open the interface connecting the sampling oil inlet pipe port 22 and the waste oil discharge pipe 21, and then the other end of the sampling oil inlet pipe port 22 is connected to the sampling valve of the transformer body, and the pressure of the transformer oil itself is used to make the oil flow out to realize the waste oil discharge at the front end. After the waste oil at the front end is discharged, the residual oil, exhaust and rinsing operations are started.

[0065] The three-way solenoid valve 2 is controlled to make the interface connecting the sampling oil inlet pipe port 22 and the sampling oil outlet pipe port 23 jammed. At this time, the limit ring 44 abuts against the side of the right limit step 238, and the first matching block 231a and the first sealing block 431 are spaced apart. The oil discharge port 232a is connected to the connecting sleeve 234. The wedge-shaped socket of the insert 234c will scrape off the residual oil on the inner wall of the corresponding connected pipe port. As the transformer oil flows out, the residual oil is carried through the adjacent first sealing blocks 431 to the adjacent first matching blocks 231a, and enters the discharge cavity 233, and then discharged through the oil discharge port 232a.

[0066] Subsequently, the blocking block 4 is located between the second matching block 234d and the first matching block 231a, and the port of the central sampling tube 231 is opened. The pressure of the transformer oil itself is used to make the oil flow out and enter the sampling cylinder 31. At this time, the piston rod 32 is driven downward by the stepper motor to prevent the piston rod 32 from blocking the oil inlet. After the sampling cylinder 31 is filled with oil, the piston rod 32 is driven upward by the stepper motor. At this time, the outer port of the connecting sleeve 234 is closed, so that the oil passes through the one-way membrane 236 and then passes through the discharge cavity 233 and is discharged from the oil discharge port 232a, thereby realizing the exhaust operation and avoiding interference caused by the air in the central sampling tube 231 and the sampling cylinder 31 when sampling.

[0067] Then repeat the above operation, and the rinsing operation is realized after 3-4 cycles of discharge. After the rinsing is completed, the oil sample in the sampling tube 31 is retained, and the sampling is completed.

[0068] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and the like, which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0069] In addition, in the description of this specification, “plurality” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. An automatic oil extraction device, comprising a sampling box and a sampler arranged in the sampling box, wherein a three-way solenoid valve is fixedly arranged in the sampling box, wherein three interfaces of the three-way solenoid valve are respectively connected to a waste oil discharge pipe, a sampling oil inlet pipe port and a sampling oil outlet pipe port, and the other end of the sampling oil outlet pipe port is connected to the sampler, characterized in that: The sampling oil outlet pipe port comprises a central sampling pipe and an outer pipe sleeve which is placed outside the central sampling pipe with an air sleeve, a drainage cavity is formed between the central sampling pipe and the outer pipe sleeve, an oil drainage port which is connected with the drainage cavity is arranged on the outer pipe sleeve, one end of the outer pipe sleeve is provided with a connecting sleeve for detachable connection with a three-way solenoid valve, the end of the connecting sleeve extends out of the end of the central sampling pipe, a blocking block is slidably arranged in the connecting sleeve, when the blocking block slides in the connecting sleeve along its axial direction, the end of the central sampling pipe which is close to the connecting sleeve is closed or opened, and at the same time, the oil drainage port is connected with or blocked from the connecting sleeve; The blocking block comprises a cylindrical plug, a limiting plate is provided at one end of the cylindrical plug away from the central sampling tube, an annular sleeve is provided at the end of the limiting plate opposite to the central sampling tube, a first sealing block is circumferentially spaced on the outer wall of the end of the annular sleeve close to the central sampling tube, one side of the first sealing block extends out of the annular sleeve along the axial direction of the annular sleeve, a first matching block is circumferentially spaced on the outer wall of the end of the central sampling tube close to the connecting sleeve, and the first matching block corresponds to between two adjacent first sealing blocks; The outer wall of the annular sleeve is provided with a connecting rod extending along its axial direction and toward a side close to the central sampling tube, the connecting rod corresponds to two adjacent first matching blocks, the free end of the connecting rod is connected with a limit stop ring, and the limit stop ring is sealingly slidably arranged in the discharge cavity; The inner wall of the outer sleeve is provided with a left limiting step and a right limiting step for matching with the limiting retaining ring; A flow guide cavity is formed on the outer wall of the outer sleeve, the oil discharge port is arranged on the outer wall of the flow guide cavity and communicated with the flow guide cavity, and a through groove for connecting the flow guide cavity and the discharge cavity is arranged on the outer sleeve.

2. The automatic oil extraction equipment according to claim 1, characterized in that: The connecting sleeve is formed with an annular groove for external plug-in matching, the outer wall of the annular groove forms a sleeve and the inner wall forms a plug, the inner wall of the outer port of the plug is circumferentially spaced with second matching blocks, the second matching blocks are arranged opposite to the first matching blocks, the limiting plate is provided with a second sealing block spaced opposite to the first sealing block, one side of the second sealing block extends out of the limiting plate along the axial direction of the cylindrical plug; The distance between the second matching block and the first matching block is greater than the length of the blocking block.

3. The automatic oil extraction equipment according to claim 2, characterized in that: The outer port of the cannula is a wedge-shaped socket.

4. The automatic oil extraction equipment according to claim 1, characterized in that: The end of the sampling oil outlet pipe close to the three-way electromagnetic valve includes an L-shaped connecting section, and the side of the limit stop ring away from the connecting sleeve is provided with an action rod corresponding to the sliding through the outer pipe sleeve.

5. The automatic oil extraction equipment according to claim 1, characterized in that: A partition between the central sampling tube and the outer tube sleeve is provided at one end of the drainage cavity close to the sampler. A through hole is provided on the partition. A one-way membrane is fixed above the partition to allow oil to flow from one side close to the sampler to the other side.

6. The automatic oil extraction equipment according to claim 1, characterized in that: The sampler comprises a sampling tube and a piston rod which is slidably arranged in the sampling tube. A power mechanism for driving the piston rod to move back and forth vertically is arranged in the sampling box.

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